JP3886810B2 - Binocular image display device - Google Patents

Description

ただし、Ｚを光の進行方向を正とした光軸（軸上主光線）とし、ｙを光軸と垂直な方向にとる。ここで、Ｒは近軸曲率半径、Ｋは円錐定数、Ａ、Ｂ、Ｃ、Ｄ、…はそれぞれ４次、６次、８次、１０次の非球面係数である。この定義式のＺ軸が回転対称非球面の軸となる。
【００３８】
なお、データの記載されていない自由曲面、非球面に関する項は０である。屈折率については、ｄ線（波長５８７．５６ｎｍ）に対するものを表記してある。長さの単位はｍｍである。
【００３９】
以下に示す数値実施例１〜３は、上記の一方の射出瞳１Ｌから画像表示素子３、３Ｌに向う逆光線追跡で表されている。
【００４０】
実施例１は、片側瞳径横４０ｍｍ、上下１５ｍｍであり、観察画像は瞳位置から４００ｍｍ前方で、水平５５ｍｍ、垂直４１．２５ｍｍの接眼光学系３２上に結像され、左右の光軸は内向角を持って接眼光学系３２から射出し、その内向角は瞳位置より接眼光学系３２側に３２０ｍｍの位置で交差する。画像表示素子３としては８．９４ｍｍ×６．７１ｍｍの表示素子を使用している。
【００４１】
図９に実施例１のＹ−Ｚ平面に投影した片方の光源（基準位置における左の照明領域）４Ｌから一方の射出瞳１Ｌに向かう光路図、図１０にそのＸ−Ｚ平面に投影した光路図、図１１にＸ−Ｚ平面に投影した両側の光源４Ｌ、４Ｒから両方の射出瞳１Ｌ、１Ｒに向かう光路図、図１２に図１１の光源４Ｌ、４Ｒ、照明光学系５、画像表示素子３、リレー光学系３１の偏心プリズム１０近傍の拡大図、図１３、図１４は図９、図１０に対応する結像光路図であり、光源４Ｌと照明光学系５を省いた図を示す。
【００４２】
後記の数値データは、左側の射出瞳１Ｌから画像表示素子３を経て一方の光源４Ｌに至るものであり、右側の射出瞳１Ｒから画像表示素子３を経て他方の光源４Ｒに至る光学系のデータは、Ｙ−Ｚ面を対称面として面対称の位置に配置したものとなる。
【００４３】
この実施例において、リレー光学系３１を構成する偏心プリズム１０の第４面１４（数値データ中の５面）は、Ｙ−Ｚ面を対称面として面対称な不連続面からなり、左側の射出瞳１Ｌの形成に関与する一方の面１４Ｌのみの面形状を示してある。この面１４ＬはＹ−Ｚ面よりＸ軸負側に設けられ、Ｙ−Ｚ面よりＸ軸正側にはそれと面対称な他方の面１４Ｒが設けられる（図１２）。第４面１４を対称面に対称な２つの光学面１４Ｌ、１４Ｒよりなる不連続面として形成することにより、本実施例の光学系の対称面（Ｙ−Ｚ面）を中心に相互に７５ｍｍは離れた横４０ｍｍ、上下１５ｍｍの瞳径の左右の射出瞳１Ｌ、１Ｒを持った光学系が構成できる。
【００４４】
実施例１の光学系は、図９〜図１４に示すように、図３の形態に対応する両眼画像表示装置用の光学系で、射出瞳１Ｌ（１Ｒ）に面した接眼光学系３２は射出瞳１Ｌ（１Ｒ）側の面がフレネル透過面、反対側の面が平面のフレネルレンズからなり、その入射側に光路折り返し用の反射面（平面鏡）３３が配置され、その反射面３３に面してリレー光学系３１が配置されている。このリレー光学系３１は画像表示素子３に面した偏心プリズム１０からなり、この実施例の偏心プリズム１０は、画像表示素子３に面する第１面１１と、反射面３３に面する第４面１４と、第１面１１と第４面１４の間に配置された２つの反射面の第２面１２、第３面１３とからなり、上記のように、第４面１４は光学系の対称面（Ｙ−Ｚ面）に対して面対称な不連続面を構成する２つの面１４Ｌ、１４Ｒからなる。
【００４５】
また、画像表示素子３は透過型液晶表示素子からなり、そのリレー光学系３１側とは反対側に、照明光学系５として両面フレネル透過面からなるフレネルレンズが画像表示素子３近傍に配置され、その前側焦点面近傍に基準位置における左右の光路用の光源４Ｌ、４Ｒが対称面（Ｙ−Ｚ面）に対して面対称な位置に配置されている。
【００４６】
この実施例においては、画像表示素子３に両眼視差のある左右の眼用の画像が交互に表示され、その切り換えに同期して左右の光路用の光源４Ｌ、４Ｒが選択的に点灯され、時分割で射出瞳１Ｌ、１Ｒに位置する左右両眼に視差のある左右の眼用の画像が表示され立体像として表示される。
【００４７】
すなわち、光源４Ｌ、４Ｒから照射された光束は、照明光学系５のフレネルレンズでそれぞれ略平行にされ、透過型液晶表示素子からなる画像表示素子３を背面から照明し、表示光は偏心プリズム１０の第１面１１で屈折してプリズム内に入射し、第２面１２と第３面１３で内部反射を繰り返し、第４面１４の２つの面１４Ｌ、１４Ｒで別々の光路に沿った光束として屈折してプリズム外に射出し、その２つの光束は反射面３３で折り返され、接眼光学系３２のフレネルレンズ面上に画像表示素子３の左右の眼用の拡大像を二重像として結像し、接眼光学系３２で屈折された光源４Ｌ、４Ｒからの光束はそれぞれ左右の射出瞳１Ｌ、１Ｒに収束する（光源４Ｌ、４Ｒと射出瞳１Ｌ、１Ｒは共役）。その際、射出瞳１Ｌ、１Ｒの位置より接眼光学系３２側に３２０ｍｍの点Ｐで左右の光軸２Ｌ、２Ｒは交差しているため、接眼光学系３２のフレネルレンズ面上に結像された両眼視差のある左右の眼用の拡大像はこの点Ｐ近傍で融像され、あたかも空中に立体像が表示されているように見える。
【００４８】
そして、本発明に基づき、図１、図２を参照にして説明したように、眼球位置検出装置４０で観察者の左右眼球位置を検出し、その情報に基づいて照明光源４の左右の照明領域である光源４Ｌ、４Ｒを移動させることにより、左右の射出瞳１Ｌ、１Ｒの位置を観察者眼球位置に追従させることができ、観察者の観察位置が変化しても左右の射出瞳１Ｌ、１Ｒを重なることなくより広範囲での立体像観察が可能となり、部品点数が少なく、サイズが小さく、消費電力の小さい両眼画像表示装置となる。
【００４９】
なお、この実施例において、接眼光学系３２の平面（数値データ中の３面）近傍に上下方向に拡散性を持ったレンチキュラーシートを配置し、上下方向にのみ瞳を拡大することによりさらに広い観察範囲を確保することができる。
【００５０】
この実施例においては、偏心プリズム１０の第１面１１〜第４面１４全てに自由曲面を用いており、接眼光学系３２及び照明光学系５のフレネルレンズのフレネル透過面には非球面を用いている。
【００５１】
実施例２は、片側瞳径横１５ｍｍ、上下１０ｍｍであり、観察画像は瞳位置から４００ｍｍ前方で、水平５５ｍｍ、垂直４１．２５ｍｍの接眼光学系３２上に結像され、左右の光軸は内向角を持って接眼光学系３２から射出し、その内向角は瞳位置より接眼光学系３２側に３２０ｍｍの位置で交差する。左右の画像表示素子３Ｌ、３Ｒとしては８．９４ｍｍ×６．７１ｍｍの表示素子を使用している。
【００５２】
図１５に実施例２のＹ−Ｚ平面に投影した片方の光源（基準位置における左の照明領域）４Ｌから一方の射出瞳１Ｌに向かう光路図、図１６にそのＸ−Ｚ平面に投影した光路図、図１７にＸ−Ｚ平面に投影した両側の光源４Ｌ、４Ｒから両方の射出瞳１Ｌ、１Ｒに向かう光路図を示す。
【００５３】
後記の数値データは、左側の射出瞳１Ｌから画像表示素子３Ｌを経て一方の光源４Ｌに至るものであり、右側の射出瞳１Ｒから画像表示素子３Ｒを経て他方の光源４Ｒに至る光学系のデータは、Ｙ−Ｚ面を対称面として面対称の位置に配置したものとなる。
【００５４】
実施例２の光学系は、図１５〜図１７に示すように、図４の形態に対応する両眼画像表示装置用の光学系で、リレー光学系３１は、Ｙ−Ｚ面を対称面として面対称の一対の偏心プリズム１０Ｌ、１０Ｒを用い、それぞれの入射面１１に面して左右別々の画像表示素子３Ｌ、３Ｒを配置し、そのための照明光学系５Ｌ、５Ｒも別々にした例である。
【００５５】
この実施例の光学系は、図１５〜図１７に示すように、射出瞳１Ｌ、１Ｒに面した接眼光学系３２は射出瞳１Ｌ、１Ｒ側の面がフレネル透過面、反対側の面が平面のフレネルレンズからなり、その入射側に光路折り返し用の反射面（平面鏡）３３が配置され、その反射面３３に面して一対の偏心プリズム１０Ｌ、１０Ｒからなるリレー光学系３１が配置されている。この実施例の偏心プリズム１０Ｌ、１０Ｒは、それぞれ画像表示素子３Ｌ、３Ｒに面する第１面１１と、反射面３３に面する第４面１４と、第１面１１と第４面１４の間に配置された２つの反射面の第２面１２、第３面１３とからなり、上記のように、偏心プリズム１０Ｌ、１０Ｒは光学系の対称面（Ｙ−Ｚ面）に対して面対称な形状になっている。
【００５６】
また、画像表示素子３Ｌ、３Ｒは透過型液晶表示素子からなり、そのリレー光学系３１側とは反対側に、それぞれ照明光学系５Ｌ、５Ｒとして両面フレネル透過面からなるフレネルレンズが画像表示素子３Ｌ、３Ｒに接して配置され、それらの前側焦点近傍に左右の光路用の基準位置における光源４Ｌ、４Ｒが対称面（Ｙ−Ｚ面）に対して面対称な位置に配置されている。
【００５７】
この実施例においては、左右の画像表示素子３Ｌ、３Ｒに両眼視差のある左右の眼用の画像を表示し、左右の照明光学系５Ｌ、５Ｒを介して左右の光源４Ｌ、４Ｒで照明し、左右の偏心プリズム１０Ｌ、１０Ｒで共通の接眼光学系３２近傍に左右の画像表示素子３Ｌ、３Ｒの像を投影し、射出瞳１Ｌ、１Ｒに位置する左右両眼に視差のある左右の眼用の画像を立体像として表示するものである。
【００５８】
すなわち、光源４Ｌ、４Ｒから照射された光束は、左右の照明光学系５Ｌ、５Ｒのフレネルレンズでそれぞれ略平行にされ、透過型液晶表示素子からなる左右の画像表示素子３Ｌ、３Ｒを背面から照明し、表示光は左右の偏心プリズム１０Ｌ、１０Ｒの第１面１１で屈折してプリズム内に入射し、第２面１２と第３面１３で内部反射を繰り返し、第４面１４で屈折してプリズム外に射出し、その２つの光束は反射面３３で折り返され、接眼光学系３２のフレネルレンズ面上に左右の画像表示素子３Ｌ、３Ｒの左右の眼用の拡大像を二重像として結像し、接眼光学系３２で屈折された光源４Ｌ、４Ｒからの光束はそれぞれ左右の射出瞳１Ｌ、１Ｒに収束する（光源４Ｌ、４Ｒと射出瞳１Ｌ、１Ｒは共役）。その際、射出瞳１Ｌ、１Ｒの位置より接眼光学系３２側に３２０ｍｍの点Ｐで左右の光軸２Ｌ、２Ｒは交差しているため、接眼光学系３２のフレネルレンズ面上に結像された両眼視差のある左右の眼用の拡大像はこの点Ｐ近傍で融像され、あたかも空中に立体像が表示されているように見える。
【００５９】
そして、本発明に基づき、図１、図２を参照にして説明したように、眼球位置検出装置４０で観察者の左右眼球位置を検出し、その情報に基づいて照明光源４の左右の照明領域である光源４Ｌ、４Ｒを移動させることにより、左右の射出瞳１Ｌ、１Ｒの位置を観察者眼球位置に追従させることができ、観察者の観察位置が変化しても左右の射出瞳１Ｌ、１Ｒを重なることなくより広範囲での立体像観察が可能となり、サイズが小さく、消費電力の小さい両眼画像表示装置となる。
【００６０】
なお、この実施例においても、接眼光学系３２の平面（数値データ中の３面）近傍に上下方向に拡散性を持ったレンチキュラーシートを配置し、上下方向にのみ瞳を拡大することによりさらに広い観察範囲を確保することができる。
【００６１】
この実施例においては、偏心プリズム１０Ｌ、１０Ｒの第１面１１〜第４面１４全てに自由曲面を用いており、接眼光学系３２及び照明光学系５のフレネルレンズのフレネル透過面には非球面を用いている。
【００６２】
実施例３は、片側瞳径１０ｍｍであり、観察画像は瞳位置から４００ｍｍ前方で、水平５５ｍｍ、垂直４１．２５ｍｍの接眼光学系３２上に結像され、左右の光軸は内向角を持って接眼光学系３２から射出し、その内向角は瞳位置より接眼光学系３２側に３２０ｍｍの位置で交差する。画像表示素子３としては８．９４ｍｍ×６．７１ｍｍの表示素子を使用している。
【００６３】
図１８に実施例３のＹ−Ｚ平面に投影した片方の光源（基準位置における左の照明領域）４Ｌから一方の射出瞳１Ｌに向かう光路図、図１９にそのＸ−Ｚ平面に投影した光路図、図２０にＸ−Ｚ平面に投影した両側の光源４Ｌ、４Ｒから両方の射出瞳１Ｌ、１Ｒに向かう光路図、図２１に図２０の光源４Ｌ、４Ｒ、照明光学系５、画像表示素子３、リレー光学系３１の偏心プリズム１０近傍の拡大図を示す。
【００６４】
後記の数値データは、左側の射出瞳１Ｌから画像表示素子３を経て一方の光源４Ｌに至るものであり、右側の射出瞳１Ｒから画像表示素子３を経て他方の光源４Ｒに至る光学系のデータは、Ｙ−Ｚ面を対称面として面対称の位置に配置したものとなる。
【００６５】
この実施例は、実施例１に対して、接眼光学系３２は射出瞳１Ｌ（１Ｒ）側の面が自由曲面の透過面２１、反対側の面がフレネル反射面２２からなるフレネル反射鏡２０を用い、光路折り返し用の反射面３３を省いた例であり、リレー光学系３１を構成する偏心プリズム１０の第４面１４（数値データ中の５面）は、Ｙ−Ｚ面を対称面として面対称な不連続面からなり、左側の射出瞳１Ｌの形成に関与する一方の面１４Ｌのみの面形状を示してある。この面１４ＬはＹ−Ｚ面よりＸ軸負側に設けられ、Ｙ−Ｚ面よりＸ軸正側にはそれと面対称な他方の面１４Ｒが設けられる（図２１）。第４面１４を対称面に対称な２つの光学面１４Ｌ、１４Ｒよりなる不連続面として形成することにより、本実施例の光学系の対称面（Ｙ−Ｚ面）を中心に相互に７５ｍｍは離れた瞳径１０ｍｍの左右の射出瞳１Ｌ、１Ｒを持った光学系が構成できる。
【００６６】
実施例３の光学系は、図１８〜図２１に示すように、射出瞳１Ｌ（１Ｒ）に面した接眼光学系３２は射出瞳１Ｌ（１Ｒ）側の面が自由曲面の透過面２１、反対側の面がフレネル反射面２２からなるフレネル反射鏡２０からなり、その反射側にリレー光学系３１が配置されている。このリレー光学系３１は画像表示素子３に面した偏心プリズム１０からなり、この実施例の偏心プリズム１０は、画像表示素子３に面する第１面１１と、接眼光学系３２に面する第４面１４と、第１面１１と第４面１４の間に配置された２つの反射面の第２面１２、第３面１３とからなり、上記のように、第４面１４は光学系の対称面（Ｙ−Ｚ面）に対して面対称な不連続面を構成する２つの面１４Ｌ、１４Ｒからなる。
【００６７】
また、画像表示素子３は透過型液晶表示素子からなり、そのリレー光学系３１側とは反対側に、照明光学系５として両面フレネル透過面からなるフレネルレンズが画像表示素子３近傍に配置され、その前側焦点面近傍に基準位置において左右の光路用の光源４Ｌ、４Ｒが対称面（Ｙ−Ｚ面）に対して面対称な位置に配置されている。
【００６８】
この実施例においては、画像表示素子３に両眼視差のある左右の眼用の画像が交互に表示され、その切り換えに同期して左右の光路用の光源４Ｌ、４Ｒが選択的に点灯され、時分割で射出瞳１Ｌ、１Ｒに位置する左右両眼に視差のある左右の眼用の画像が表示され立体像として表示される。
【００６９】
すなわち、光源４Ｌ、４Ｒから照射された光束は、照明光学系５のフレネルレンズでそれぞれ略平行にされ、透過型液晶表示素子からなる画像表示素子３を背面から照明し、表示光は偏心プリズム１０の第１面１１で屈折してプリズム内に入射し、第２面１２と第３面１３で内部反射を繰り返し、第４面１４の２つの面１４Ｌ、１４Ｒで別々の光路に沿った光束として屈折してプリズム外に射出し、その２つの光束は接眼光学系３２のフレネル反射鏡２０の透過面２１上に画像表示素子３の左右の眼用の拡大像を二重像として結像し、接眼光学系３２で反射された光源４Ｌ、４Ｒからの光束はそれぞれ左右の射出瞳１Ｌ、１Ｒに収束する（光源４Ｌ、４Ｒと射出瞳１Ｌ、１Ｒは共役）。その際、射出瞳１Ｌ、１Ｒの位置より接眼光学系３２側に３２０ｍｍの点Ｐで左右の光軸２Ｌ、２Ｒは交差しているため、フレネル反射鏡２０の透過面２１上に結像された両眼視差のある左右の眼用の拡大像はこの点Ｐ近傍で融像され、あたかも空中に立体像が表示されているように見える。
【００７０】
そして、本発明に基づき、図１、図２を参照にして説明したように、眼球位置検出装置４０で観察者の左右眼球位置を検出し、その情報に基づいて照明光源４の左右の照明領域である光源４Ｌ、４Ｒを移動させることにより、左右の射出瞳１Ｌ、１Ｒの位置を観察者眼球位置に追従させることができ、観察者の観察位置が変化しても左右の射出瞳１Ｌ、１Ｒを重なることなくより広範囲での立体像観察が可能となり、部品点数が少なく、サイズが小さく、消費電力の小さい両眼画像表示装置となる。
【００７１】
この実施例においては、偏心プリズム１０の第１面１１〜第４面１４全てに自由曲面を用いており、フレネル反射鏡２０の透過面２１に自由曲面を用いており、フレネル反射鏡２０のフレネル反射面２２及び照明光学系５のフレネルレンズのフレネル透過面には非球面を用いている。
【００７２】
以下に各実施例の数値データを示すが、以下の表中の“ＦＦＳ”は自由曲面、“ＡＳＳ”は非球面、“ＲＥ”は反射面、“ＦＲ”はフレネル面、“ＬＣＤ”は画像表示面、“ＥＩＭ”は結像面をそれぞれ示す。
【００７３】

【００７４】

【００７５】

【００７６】
上記実施例１の片側の光学系の横収差を図２２に示す。この横収差図において、括弧内に示された数字は（水平画角，垂直画角）を表し、その画角における横収差を示す。
【００７７】
ところで、以上の３つの実施例は何れも、画像表示素子３、３Ｌ、３Ｒとしては透過型液晶表示素子を用いているが、その代わりに反射型液晶表示素子、ＤＭＤ（ディジタルマイクロミラーデバイス）等の反射型画像表示素子を用いて、より小型でコンパクトな構成で、かつ、低消費電力で、立体視可能な画像表示装置を構成することができる。その場合には、図５に例示したように、リレー光学系３１を構成する偏心プリズム１０、１０Ｌ、１０Ｒの一部又は全部を介して、照明光源４の左右の照明領域４Ｌ、４Ｒからの照明光を反射型画像表示素子３の表示面に照射し、その表示面で変調された表示光を再びそのリレー光学系３１の偏心プリズム１０、１０Ｌ、１０Ｒに入射させて左右の射出瞳１Ｌ、１Ｒに至る光軸２Ｌ、２Ｒに沿って投影させるようにする。
【００７８】
ところで、眼球位置検出装置４０で検出された観察者の左右眼球位置情報に基づいて照明領域４Ｌ、４Ｒを任意に移動できる照明光源４としては、ＬＥＤの２次元アレイ、２次元有機ＥＬ、バックライトで照射される透過型液晶表示素子等を用いることができるが、面光源の前に一対の開口を配置してその開口を機械的に移動できるもの、あるいは、一対の機械的に移動可能な点光源からなるものであってもよい。
【００７９】
なお、照明領域４Ｌ、４Ｒの移動範囲は、リレー光学系３１と接眼光学系３２で光線がケラレない範囲で移動できる。
【００８０】
また、本発明の両眼画像表示装置のリレー光学系に用いる偏心プリズム光学系としては、以上の実施例１〜３で用いたタイプに限定されず、他のタイプの偏心プリズム単体あるいはそれらの偏心プリズムの組み合わせからなる光学系を用いることができる。
【００８１】
以上の本発明の両眼画像表示装置は例えば次のように構成することができる。
【００８２】
〔１〕 画像を表示する画像表示素子と、照明光源と、前記照明光源からの照明光を前記画像表示素子に向けて照射する照明光学系と、前記画像表示素子により変調された表示光を投影して前記画像表示素子に表示された画像を投影するリレー光学系と、前記リレー光学系からの光束を射出瞳に収束させる接眼光学系とを有する画像表示装置において、
前記画像表示素子は左右の眼用の画像を交互に表示する単一の画像表示素子からなり、
前記照明光源は、前記画像表示素子に表示された左右の眼用の画像に応じて別々の照明領域に切り換えられ、かつ、その照明領域を移動させることができる光源からなり、
前記射出瞳は、前記照明光源の照明領域に応じて定まる左右の一対の射出瞳からなり、
さらに、観察者の左右の眼球位置を検出する眼球位置検出装置を有し、
前記眼球位置検出装置により検出された前記観察者の左右の眼球位置に前記左右の一対の射出瞳が略一致するように、前記眼球位置検出装置により検出された前記観察者の左右の眼球位置情報に基づき、前記照明光源の照明領域を移動させることを特徴とする両眼画像表示装置。
【００８３】
〔２〕 前記リレー光学系は、前記画像表示素子に表示された左右の眼用の画像を前記接眼光学系近傍に結像するように構成されていることを特徴とする上記１記載の両眼画像表示装置。
【００８４】
〔３〕 前記リレー光学系は、前記画像表示素子に表示された画像を物点としてその物点から発する光束を２つの光路に分割する光学系からなることを特徴とする上記１又は２記載の両眼画像表示装置。
【００８５】
〔４〕 前記リレー光学系は、屈折率（ｎ）が１よりも大きい（ｎ＞１）媒質で形成された偏心プリズムを有し、その偏心プリズムが、前記物点から発せられた光束をプリズム内に入射する入射面と、その光束をプリズム内で反射する少なくとも１つの反射面と、光束をプリズム外に射出する射出面とを有し、かつ、少なくとも１つの回転非対称面を有し、少なくとも１つの光学作用面は隣接する少なくとも２つの面からなる不連続面で構成され、他の光学作用面は分割された少なくとも２つの光路内に共通に配置されてなることを特徴とする上記３記載の両眼画像表示装置。
【００８６】
〔５〕 前記画像表示素子が反射型画像表示素子からなり、前記偏心プリズムの一部又は全部を介して、前記照明光源の前記照明領域からの照明光が前記反射型画像表示素子に照射されることを特徴とする上記４記載の両眼画像表示装置。
【００８７】
〔６〕 前記画像表示素子が透過型画像表示素子からなることを特徴とする上記１から４の何れか１項記載の両眼画像表示装置。
【００８８】
〔７〕 前記照明光源は、照明領域を任意の位置に設定可能な面光源からなることを特徴とする上記１から５の何れか１項記載の両眼画像表示装置。
【００８９】
〔８〕 画像を表示する画像表示素子と、照明光源と、前記照明光源からの照明光を前記画像表示素子に向けて照射する照明光学系と、前記画像表示素子により変調された表示光を投影して前記画像表示素子に表示された画像を投影するリレー光学系と、前記リレー光学系からの光束を射出瞳に収束させる接眼光学系とを有する画像表示装置において、
前記画像表示素子は左右の眼用の画像を表示する一対の画像表示素子からなり、
前記照明光源は、前記一対の画像表示素子に対応した別々の照明領域を備え、かつ、その照明領域を移動させることができる光源からなり、
前記射出瞳は、前記照明光源の照明領域に応じて定まる左右の一対の射出瞳からなり、
さらに、観察者の左右の眼球位置を検出する眼球位置検出装置を有し、
前記眼球位置検出装置により検出された前記観察者の左右の眼球位置に前記左右の一対の射出瞳が略一致するように、前記眼球位置検出装置により検出された前記観察者の左右の眼球位置情報に基づき、前記照明光源の照明領域を移動させることを特徴とする両眼画像表示装置。
【００９０】
〔９〕 前記リレー光学系は、前記画像表示素子に表示された左右の眼用の画像を前記接眼光学系近傍に結像するように構成されていることを特徴とする上記８記載の両眼画像表示装置。
【００９１】
〔１０〕 前記リレー光学系は、前記画像表示素子に表示された左右の眼用の画像各々を物点としてそれら物点から発する光束を別々の光路に導く光学系からなることを特徴とする上記８又は９記載の両眼画像表示装置。
【００９２】
〔１１〕 前記リレー光学系は、屈折率（ｎ）が１よりも大きい（ｎ＞１）媒質で形成された一対の偏心プリズムを有し、各偏心プリズムは、対応する画像表示素子から射出された光束をプリズム内に入射する入射面と、その光束をプリズム内で反射する少なくとも１つの反射面と、光束をプリズム外に射出する射出面とを有し、その少なくとも１つの反射面が光束にパワーを与える回転非対称面からなることを特徴とする上記１０記載の両眼画像表示装置。
【００９３】
〔１２〕 前記画像表示素子が反射型画像表示素子からなり、前記偏心プリズムの一部又は全部を介して、前記照明光源の前記照明領域からの照明光が前記反射型画像表示素子に照射されることを特徴とする上記１１記載の両眼画像表示装置。
【００９４】
〔１３〕 前記画像表示素子が透過型画像表示素子からなることを特徴とする上記８から１１の何れか１項記載の両眼画像表示装置。
【００９５】
〔１４〕 前記照明光源は、照明領域を任意の位置に設定可能な面光源からなることを特徴とする上記８から１３の何れか１項記載の両眼画像表示装置。
【００９６】
【発明の効果】
以上の説明から明らかなように、本発明により、観察者の観察位置が動いても右眼用の瞳と左眼用の瞳を重なることなく追従させることでより広範囲での立体視等ができ、小型で部品点数が少なく、携帯可能な両眼画像表示装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の両眼画像表示装置の基本形態を示す模式的斜視図である。
【図２】本発明の両眼画像表示装置の作用を詳しく説明するための図である。
【図３】リレー光学系を単一の偏心プリズムから構成する場合の両眼画像表示装置の構成を示す模式的斜視図である。
【図４】リレー光学系を一対の偏心プリズムから構成する場合の両眼画像表示装置の構成を示す模式的斜視図である。
【図５】リレー光学系を構成する単一の偏心プリズムの例示と画像表示素子を反射型で構成する場合の照明光源の配置と照明光の導入方法の例示を示す模式的斜視図である。
【図６】左右に長い楕円にして形成される射出瞳を示す図である。
【図７】接眼光学系に配置される拡散性の光学面の拡散性を説明するための図である。
【図８】手持ちビュワータイプの形態に構成された本発明の両眼画像表示装置を示す模式的斜視図である。
【図９】本発明の実施例１の光学系のＹ−Ｚ平面に投影した片方の光源から一方の射出瞳に向かう光路図である。
【図１０】実施例１の光学系のＸ−Ｚ平面に投影した光路図である。
【図１１】実施例１の光学系のＸ−Ｚ平面に投影した両側の光源から両方の射出瞳に向かう光路図である。
【図１２】図１１の光源、照明光学系、画像表示素子、リレー光学系の偏心プリズム近傍の拡大図である。
【図１３】図９に対応する結像光路図である。
【図１４】図１０に対応する結像光路図である。
【図１５】実施例２の光学系のＹ−Ｚ平面に投影した片方の光源から一方の射出瞳に向かう光路図である。
【図１６】実施例２の光学系のＸ−Ｚ平面に投影した光路図である。
【図１７】実施例２の光学系のＸ−Ｚ平面に投影した両側の光源から両方の射出瞳に向かう光路図である。
【図１８】実施例３の光学系のＹ−Ｚ平面に投影した片方の光源から一方の射出瞳に向かう光路図である。
【図１９】実施例３の光学系のＸ−Ｚ平面に投影した光路図である。
【図２０】実施例３の光学系のＸ−Ｚ平面に投影した両側の光源から両方の射出瞳に向かう光路図である。
【図２１】図２０の光源、照明光学系、画像表示素子、リレー光学系の偏心プリズム近傍の拡大図である。
【図２２】実施例１の片側の光学系の横収差を示す図である。
【符号の説明】
１Ｌ、１Ｒ…射出瞳
２Ｌ、２Ｒ…光軸
３、３Ｌ、３Ｒ…画像表示素子
４…照明光源
４Ｌ、４Ｒ…照明領域
５、５Ｌ、５Ｒ…照明光学系
１０、１０Ｌ、１０Ｒ…偏心プリズム
１１…第１面
１２…第２面
１３…第３面
１４…第４面
１４Ｌ、１４Ｒ…不連続面を構成する光学面
２０…フレネル反射鏡
２１…接眼光学系の射出瞳側の透過面
２２…接眼光学系の反対側のフレネル反射面
３０…表示装置本体
３１…リレー光学系
３２…接眼光学系
３３…反射面（平面鏡）
３４…操作ボタン
４０…眼球位置検出装置
４１…撮像装置
４２…映像処理装置
４３…制御装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a binocular image display device, and more particularly to an image display device capable of observing a stereoscopic image or the like by guiding left and right eye images displayed on an image display element to the left and right eyes. The present invention relates to an image display apparatus.
[0002]
[Prior art]
As a small display device, a direct-view type liquid crystal display device is often used as a mobile phone or a mobile terminal. However, in order to display a high-definition display or a moving image with a large number of pixels, it is necessary to use an expensive active matrix liquid crystal having a high display speed, which causes a problem that the display device is expensive. In addition, power consumption is large, and in order to display for a long time, a battery having a large capacity is required, and a large and heavy battery is required. Furthermore, there was a concern that the display contents could be peeped by people around.
[0003]
On the other hand, there are also those disclosed in Japanese Patent Application Laid-Open No. 48-102527 and those disclosed in Japanese Patent Application Laid-Open No. 5-303054 by the applicant of the present invention for enlarging display with an optical system using a small display element. These display an enlarged display of a display device as a virtual image using a concave mirror. In particular, the latter uses a non-rotationally symmetric reflecting surface to obtain a projection image with little aberration. However, the display element needs to have a relatively large size, and a display element that is particularly small compared to a direct-view display device cannot be used, and the original purpose cannot be achieved.
[0004]
Next, there is a method of projecting the image of the display element once in the air by the projection optical system disclosed in Japanese Patent Application Laid-Open Nos. 5-303055 and 2000-212440 by the present applicant, and further enlarging and displaying the image with a concave mirror. Proposed. Examples of the apparatus include those disclosed in JP-A-7-270781 and JP-A-9-139901.
[0005]
Further, in the Japanese Patent Application No. 2001-66669, the present applicant projects an image displayed on the display element or an intermediate image thereof by a relay optical system including a decentered prism optical system, and transmits a light beam from the relay optical system to the eyepiece optical system. Has proposed a small and low power consumption display device that converges toward the observer's eyeball. This display device projects a projection image in the vicinity of an eyepiece optical system by a relay optical system, and projects an exit pupil of the relay optical system on an observer's eyeball.
[0006]
Further, in Japanese Patent Laid-Open No. 9-5670, a surface light source is used as a backlight in order to cause a binocular parallax image displayed in a surface sequence on one display element to enter the left and right eyes, respectively. A device that illuminates a region corresponding to the left and right eyes according to a display image is known.
[0007]
[Problems to be solved by the invention]
However, in the case of Japanese Patent Laid-Open No. 9-5670, a method of illuminating a transmissive display element with a backlight is used. However, since the backlight is used, the use efficiency of light is poor and the image becomes dark. End up. In addition, although the image becomes brighter by using the illumination optical system, the apparatus becomes larger due to the optical path length of the illumination optical system, which is not suitable for portable use.
[0008]
By the way, in the case of configuring an image display device that can be observed with both eyes by an optical system composed of a relay optical system and an eyepiece optical system, even in a configuration in which images for the left and right eyes are displayed in a plane order on one display element, In both configurations in which left and right eye images are simultaneously displayed on a pair of left and right display elements, when performing binocular stereoscopic vision, the right and left eye exit pupils, which are observable regions, overlap. Since the observed image becomes a double image (crosstalk), in order to avoid such crosstalk, in the conventional stereoscopic vision, the observable area of the stereoscopic image is in the left-right direction of the face. It was limited to about half the width and very narrow. In addition, when the observer's eyes deviate from the exit pupil, stereoscopic viewing is no longer possible.
[0009]
The present invention has been made to solve the above-described problems of the prior art, and its object is to form a three-dimensional image of a relay optical system and a light beam from the relay optical system directed to both eyes of an observer by an eyepiece optical system. In a binocular image display device that can be viewed, etc., even if the observer's observation position moves, both the right-eye pupil and the left-eye pupil can be followed without overlapping so that stereoscopic viewing can be performed over a wider range. An eye image display device is provided.
[0010]
[Means for Solving the Problems]
The first binocular image display device of the present invention that achieves the above object includes an image display element that displays an image, an illumination light source, and illumination optics that irradiates illumination light from the illumination light source toward the image display element. In an image display apparatus comprising: a system; a relay optical system that projects an image displayed on the image display element; and an eyepiece optical system that converges a light beam from the relay optical system to an exit pupil position;
The image display element comprises a single element that alternately displays images for left and right eyes,
The illumination light source is configured to be able to switch the illumination area according to the left and right eye images, and to be able to move the illumination area,
The exit pupil position is a conjugate position with the illumination area of the illumination light source, and a pair of left and right exit pupils are formed at the exit pupil position,
The shape of the exit pupil of the relay optical system formed at the exit pupil position is an ellipse that is long to the left and right,
The eyepiece optical system has a diffusive optical surface;
The diffusive optical surface is a surface having a diffusing action in the up-down direction and hardly diffusing in the left-right direction,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
Illumination of the illumination light source based on the left and right eyeball position information of the observer so that the positions of the left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection device. The region is moved.
[0011]
The second binocular image display device of the present invention includes an image display element that displays an image, an illumination light source, an illumination optical system that irradiates illumination light from the illumination light source toward the image display element, and the image. In an image display device having a relay optical system that projects an image displayed on a display element, and an eyepiece optical system that converges a light beam from the relay optical system to an exit pupil position,
The image display element is composed of a pair of elements for displaying left and right eye images,
The illumination light source includes separate illumination areas corresponding to the pair of elements, and is configured to be movable in the illumination areas.
The exit pupil position is a conjugate position with the illumination area of the illumination light source, and a pair of left and right exit pupils are formed at the exit pupil position,
The shape of the exit pupil of the relay optical system formed at the exit pupil position is an ellipse that is long to the left and right,
The eyepiece optical system has a diffusive optical surface;
The diffusive optical surface is a surface having a diffusing action in the up-down direction and hardly diffusing in the left-right direction,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
Illumination of the illumination light source based on the left and right eyeball position information of the observer so that the positions of the left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection device. The region is moved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The principle and examples of the binocular image display device of the present invention will be described below.
[0013]
First, the basic form of the binocular image display device of the present invention will be described.
[0014]
In the basic form of the binocular image display device of the present invention, as shown in FIG. 1, a relay optical system 31 is arranged on a main body 30, and a single or a pair of image display elements 3 (in the case of the figure) at the position of the object. Is assumed to be a single image display element) and behind the image display element 3 (in the case where the image display element 3 is a transmissive type, the case of a reflective type will be described with reference to FIG. 3). ), The illumination optical system 5 (see FIGS. 10 to 12 and the like) not shown, and the illumination light source 4 composed of a surface light source are arranged, and the eyepiece optical having positive power on the exit side of the relay optical system 31 A system 32 is arranged. The display light emitted from the left and right illumination regions 4L and 4R (see FIG. 2) of the illumination light source 4 and emitted from the image display element 3 illuminated with the illumination light that has passed through the illumination optical system 5 passes through the relay optical system 31 and 2 The left and right exit pupils 1L and 1R are formed in the vicinity of the observer's eyes by the eyepiece optical system 32 along the two optical axes 2L and 2R.
[0015]
Here, the left and right exit pupils 1L and 1R and the left and right illumination areas 4L and 4R of the illumination light source 4 are set at optically conjugate positions.
[0016]
In this way, the illumination light emitted from the illumination light source 4 is modulated by the image display element 3 and guided along the left and right optical axes 2L and 2R via the relay optical system 31 and the eyepiece optical system 32, and left and right of the image display device. By projecting onto the exit pupils 1L and 1R, illumination light can be projected onto both eyes without waste, and a bright and efficient stereoscopic image can be enlarged and displayed.
[0017]
By the way, if the positions of both eyes of the observer that should be positioned at the exit pupils 1L and 1R are deviated, the left and right exit pupils will enter one eye of the observer and a double image can be seen or observation becomes difficult at all. In the present invention, an eyeball position detection device 40 for detecting the left and right eyeball positions of the observer is provided, the left and right eyeball positions of the observer are detected by the detection device 40, and the left and right eyeball positions have left and right optical axes. By controlling the left and right illumination areas 4L and 4R (FIG. 2) of the illumination light source 4 so that 2L and 2R match, even if the observation position changes, the left and right exit pupils 1L and 1R are caused to follow without overlapping. This makes it possible to observe a stereoscopic image in a wider range. Here, the eyeball position detection device 40 is based on the imaging device 41, a video processing device 42 that processes an eyeball image captured by the imaging device 41 and identifies an eyeball position, and eyeball position information obtained by the video processing device 42. The control device 43 that controls the positions of the light emission (illumination) regions 4L and 4R of the illumination light source 4 and the illumination light source 4 whose light emission region is controlled by the control device 43.
[0018]
The operation of this device will be described in more detail with reference to FIG.
[0019]
In FIG. 2, unlike FIG. 1, the eyeball position detection device 40 is not shown, and the eyepiece optical system 32 is shown as a reflection type (in the case of FIG. 1, a transmission type). The configuration is the same. As shown in FIG. 2, the left and right illumination areas of the illumination light source 4 which is a surface light source are 4L. _A 4R _A To 4L _B 4R _B The left and right optical axes toward the left and right exit pupils are 2L. _A 2R _A To 2L _B 2R _B The left and right exit pupils are 1L accordingly. _A 1R _A To 1L _B 1R _B To change. Thus, the left and right illumination areas 4L, 4R (4L _A 4R _A ; 4L _B 4R _B ) By moving the left and right exit pupils 1L, 1R (1L _A 1R _A 1L _B 1R _B ) Can also be moved, as described above, the left and right eyeball positions of the observer are detected by the eyeball position detection device 40, and the left and right illumination areas 4L and 4R of the illumination light source 4 are moved based on the information. Thus, the positions of the left and right exit pupils 1L and 1R can be made to follow the observer eyeball position. As a result, as described above, even when the observation position changes, it is possible to observe a stereoscopic image in a wider range without overlapping the left and right exit pupils 1L and 1R.
[0020]
In the case of FIG. 1, the left and right optical axes 2L and 2R emitted from the relay optical system 31 are folded back by the reflecting surface 33 and guided to the observer's eyes by the transmission type (refractive type) eyepiece optical system 32. However, in the case of FIG. 2, the reflection surface 33 is not necessary because the reflection type eyepiece optical system 32 is used as described above. In the case of FIG. 1, the operation button 34 is disposed on the main body 30 of the display device in front of the relay optical system 31 when viewed from the observer side. With this arrangement, it is possible to avoid the problem of blocking the image every time the button is operated without blocking the light path by the hand operating the operation button 34.
[0021]
By the way, as a possible form when the relay optical system 31 is configured by a decentered prism, as shown in FIG. 3, a case where the relay optical system 31 is composed of a single decentered prism 10 and a pair of left and right identical as shown in FIG. The decentering prisms 10L and 10R may be used. In the case of the single decentered prism 10 in the case of FIG. 3, as schematically shown in FIG. 5 as an example, it has an entrance surface 11, an exit surface 14, and two internal reflection surfaces 12 and 13, and an image. The optical axes (axial principal rays) 2L, 2R emitted from the display element 3 are configured to substantially intersect in the optical system, and the exit surface 14 is configured by a discontinuous surface composed of two adjacent surfaces 14L, 14R. is doing. Of course, one or more of the other optical surfaces 11 to 13 may be formed of a discontinuous surface composed of such two surfaces.
[0022]
In FIG. 1 and FIG. 2, a transmissive type is assumed as the image display element 3, but a small-sized image display device can be formed using the reflective image display element 3. When a decentered prism is used as the relay optical system 31, the distance between the reflective image display element 3 and the relay optical system 31 is usually small. Therefore, as illustrated in FIG. The display surface of the reflective image display element 3 is irradiated with illumination light from the left and right illumination regions 4L, 4R of the illumination light source 4 of the surface light source through a part or all of the decentering prism 10 constituting the display prism. It is desirable that the display light modulated in step (b) is incident again on the eccentric prism 10 of the relay optical system 31 and projected along the optical axes 2L and 2R reaching the left and right exit pupils 1L and 1R. In the case of FIG. 5, the internal reflection surface 12 is constituted by a half mirror, and the illumination light from the illumination light source 4 is incident on the eccentric prism 10 through the half mirror surface 12, and the illumination is incident from the incident surface 11 to the outside of the prism. Light is emitted to illuminate the display surface of the reflective image display element 3.
[0023]
As shown in FIG. 3, when the relay optical system 31 is configured by a single decentered prism 10 having a discontinuous surface composed of two adjacent surfaces, at least one optical action surface (reflecting surface or refracting surface). In this case, as the image display element 3, a single image display element is arranged on the object plane, and images for right and left eyes having binocular parallax are alternately displayed.
[0024]
As shown in FIG. 4, when the same pair of left and right decentered prisms 10L and 10R are used as the relay optical system 31, separate image display elements 3 are arranged on the object surfaces of the decentered prisms 10L and 10R. The left and right eye images with binocular parallax are respectively displayed.
[0025]
By the way, the right and left exit pupils 1L and 1R are mixed (overlapped) in the eyepiece optical system 32 arranged in the vicinity of the position where the image of the left and right eye images having binocular parallax is formed by the relay optical system 31. By disposing a diffusive optical surface with directivity suppressed in a range that is not allowed to increase, the light flux toward the exit pupils 1L and 1R is thickened, thereby expanding the range of the exit pupils 1L and 1R and displaying an image with both eyes. The range that can be observed can be expanded.
[0026]
In this case, the shape of the left and right exit pupils 1L and 1R of the relay optical system 31 formed at the positions of the exit pupils 1L and 1R by the eyepiece optical system 32 when there is no diffusibility is as shown in FIG. It is desirable that the left and right exit pupils 1L and 1R have large diameters that are long in the left and right directions, and the diffusive optical surface disposed in the eyepiece optical system 32 is as shown in FIG. If the surface has a diffusing action in the up and down direction and hardly has a diffusing action in the left and right direction as shown in FIG. 7B, the light quantity is not wasted and it is not darkened, and the exit pupils 1L and 1R The range in which the image can be observed with both eyes is expanded by expanding the range vertically and horizontally.
[0027]
As the relay optical system 31 in the present invention, various decentered prism optical systems having a number of internal reflections of one or more already proposed by the present inventors or the like can be used. Among them, as a typical example, it includes two reflecting surfaces like the decentered prisms of Examples 1 to 3 described later, and includes an incident surface, a first reflecting surface, a second reflecting surface, and an exit surface. An optical path connecting the incident surface and the first reflecting surface intersects with the optical path connecting the second reflecting surface and the exit surface in the prism.
[0028]
Such a decentered prism has a high degree of freedom in correcting aberrations and produces less aberrations. Further, since the arrangement of the two reflecting surfaces is highly symmetric, the aberration generated on the two reflecting surfaces is corrected between the two reflecting surfaces, and the occurrence of aberration is small. In addition, because the optical path forms a crossed optical path in the prism, the optical path length can be made longer compared to a prism with a structure that simply folds the optical path, and the prism is downsized for the length of the optical path length. can do.
[0029]
When any of the decentering prisms 10 is constituted by a single decentering prism 10 as shown in FIG. 3, at least one optical action surface (reflecting surface or refracting surface) is not formed of two adjacent surfaces. By constituting as a continuous surface, the light beam from the image display element 3 is divided into two optical paths.
[0030]
The binocular image display device of the present invention is provided with a mechanism for opening and closing the eyepiece optical system 32 and the reflecting surface 33 of FIGS. 1 to 4 with respect to the main body 30 of the display device, and is stored in a pocket or the like when being carried. It becomes possible to comprise. At this time, if a function for cutting off the power supply is added, the power saving effect is high.
[0031]
Further, the present invention is not limited to such a portable type of use, and can be configured as a hand-held viewer type as shown in FIG.
[0032]
Next, numerical examples 1 to 3 of the optical system used in the binocular image display device of the present invention will be described.
[0033]
Although the configuration parameters of Examples 1 to 3 will be described later, as shown in FIGS. 9 to 21, the coordinate system is between two left and right exit pupils 1 </ b> L and 1 </ b> R (FIG. 1) (observer pupil). A plane that passes through the center and is perpendicular to a straight line connecting the centers of the exit pupils 1L and 1R and that forms a symmetry plane of the optical system is defined as a YZ plane, and travels from the center of the exit pupils 1L and 1R toward the eyepiece optical system 32. The direction is the Z-axis positive direction, the direction orthogonal to the Z-axis direction is the Y-axis direction, the direction toward the image display element 3 side is the Y-axis negative direction, and the direction orthogonal to the YZ plane is the X-axis Direction, and the Y-axis, Z-axis and the X-axis direction constituting the right-handed orthogonal coordinate system are defined as the X-axis positive direction. The origin of the optical system is set as the top position of the surface of the eyepiece optical system 32 on the exit pupil 1L, 1R side.
[0034]
For the eccentric surface, the amount of eccentricity from the center of the origin of the optical system to the top position of the surface (X, Y, and Z directions are X, Y, and Z, respectively) and the center axis of the surface (free For curved surfaces, the Z-axis in the above equation (a), and for aspherical surfaces, the Z-axis in the later-described equation (b))) is tilted around the X-axis, Y-axis, and Z-axis (α, β respectively) , Γ (°)). In this case, positive α and β mean counterclockwise rotation with respect to the positive direction of each axis, and positive γ means clockwise rotation with respect to the positive direction of the Z axis. Note that the α, β, and γ rotations of the central axis of the surface are performed by first rotating the central axis of the surface and its XYZ orthogonal coordinate system by α counterclockwise around the X axis, and then rotating the rotation. The center axis of the surface is rotated β counterclockwise around the Y axis of the new coordinate system, and the coordinate system rotated once is also rotated β counterclockwise around the Y axis and then rotated twice. The center axis of the surface is rotated γ clockwise around the Z axis of the new coordinate system.
[0035]
Further, the shape of the surface of the free-form surface used in the present invention is a free-form surface defined by, for example, the equation (a) of US Pat. No. 6,124,989 (Japanese Patent Laid-Open No. 2000-66105). The Z-axis is the axis of the free-form surface.
[0036]
An aspherical surface is a rotationally symmetric aspherical surface given by the following definition.
[0037]

However, Z is an optical axis (axial principal ray) with the light traveling direction being positive, and y is a direction perpendicular to the optical axis. Here, R is a paraxial radius of curvature, K is a conic constant, A, B, C, D,... Are fourth-order, sixth-order, eighth-order, and tenth-order aspherical coefficients, respectively. The Z axis of this defining formula is the axis of a rotationally symmetric aspherical surface.
[0038]
Note that terms relating to free-form surfaces and aspheric surfaces for which no data is described are zero. The refractive index is shown for d-line (wavelength 587.56 nm). The unit of length is mm.
[0039]
Numerical examples 1 to 3 shown below are expressed by back ray tracing from the one exit pupil 1L to the image display elements 3 and 3L.
[0040]
Example 1 has a one-sided pupil diameter of 40 mm and an upper and lower side of 15 mm, and an observation image is formed on the eyepiece optical system 32 having a horizontal size of 55 mm and a vertical size of 41.25 mm, 400 mm forward from the pupil position, and the left and right optical axes are inward. It exits from the eyepiece optical system 32 with an angle, and its inward angle intersects the eyepiece optical system 32 side from the pupil position at a position of 320 mm. As the image display element 3, a display element of 8.94 mm × 6.71 mm is used.
[0041]
FIG. 9 is an optical path diagram from one light source (left illumination area at the reference position) 4L projected onto the YZ plane of the first embodiment to one exit pupil 1L, and FIG. 10 is an optical path projected onto the XZ plane. 11 and FIG. 11 are optical path diagrams from the light sources 4L and 4R on both sides projected to the XZ plane to both exit pupils 1L and 1R. FIG. 12 shows the light sources 4L and 4R, the illumination optical system 5, and the image display element in FIG. 3 is an enlarged view of the vicinity of the decentering prism 10 of the relay optical system 31, and FIGS. 13 and 14 are image-forming optical path diagrams corresponding to FIGS. 9 and 10, in which the light source 4L and the illumination optical system 5 are omitted.
[0042]
The numerical data described later is data from the left exit pupil 1L through the image display element 3 to one light source 4L, and optical system data from the right exit pupil 1R through the image display element 3 to the other light source 4R. Is arranged in a plane-symmetrical position with the YZ plane as the plane of symmetry.
[0043]
In this embodiment, the fourth surface 14 (five surfaces in the numerical data) of the decentering prism 10 constituting the relay optical system 31 is a discontinuous surface that is symmetrical with respect to the YZ plane, and is emitted on the left side. Only the surface shape of one surface 14L involved in the formation of the pupil 1L is shown. The surface 14L is provided on the X axis negative side from the YZ plane, and the other surface 14R that is plane-symmetric with respect to the YZ plane is provided on the X axis positive side (FIG. 12). By forming the fourth surface 14 as a discontinuous surface composed of two optical surfaces 14L and 14R that are symmetrical with respect to the symmetry plane, 75 mm can be obtained around the symmetry surface (YZ surface) of the optical system of the present embodiment. An optical system having left and right exit pupils 1L, 1R having a pupil diameter of 40 mm apart and 15 mm above and below can be configured.
[0044]
The optical system of Example 1 is an optical system for a binocular image display device corresponding to the form of FIG. 3 as shown in FIGS. 9 to 14, and an eyepiece optical system 32 facing the exit pupil 1L (1R) is The exit pupil 1L (1R) side surface is a Fresnel transmission surface, and the opposite surface is a flat Fresnel lens. A reflection surface (plane mirror) 33 for returning the optical path is disposed on the incident side. Thus, the relay optical system 31 is arranged. The relay optical system 31 includes a decentered prism 10 facing the image display element 3, and the decentered prism 10 of this embodiment includes a first surface 11 facing the image display element 3 and a fourth surface facing the reflecting surface 33. 14 and the second surface 12 and the third surface 13 of the two reflecting surfaces arranged between the first surface 11 and the fourth surface 14, and as described above, the fourth surface 14 is symmetrical with the optical system. It consists of two surfaces 14L and 14R that constitute a discontinuous plane that is plane-symmetric with respect to the plane (YZ plane).
[0045]
Further, the image display element 3 is composed of a transmissive liquid crystal display element, and on the side opposite to the relay optical system 31 side, a Fresnel lens comprising a double-sided Fresnel transmissive surface as the illumination optical system 5 is disposed in the vicinity of the image display element 3. Near the front focal plane, the light sources 4L and 4R for the left and right optical paths at the reference position are arranged at positions symmetrical with respect to the symmetry plane (YZ plane).
[0046]
In this embodiment, left and right eye images with binocular parallax are alternately displayed on the image display element 3, and the light sources 4L and 4R for the left and right optical paths are selectively lit in synchronization with the switching, The right and left eye images with parallax are displayed on the left and right eyes located at the exit pupils 1L and 1R in a time-sharing manner and displayed as a stereoscopic image.
[0047]
That is, the light beams emitted from the light sources 4L and 4R are made substantially parallel by the Fresnel lens of the illumination optical system 5, respectively, illuminate the image display element 3 composed of a transmissive liquid crystal display element from the back, and the display light is decentered prism 10. The first surface 11 is refracted and incident on the prism, the internal reflection is repeated on the second surface 12 and the third surface 13, and the two surfaces 14L and 14R of the fourth surface 14 as light beams along different optical paths. The two light beams are refracted and emitted out of the prism, and the two light fluxes are folded back by the reflecting surface 33. The enlarged images for the left and right eyes of the image display element 3 are formed as double images on the Fresnel lens surface of the eyepiece optical system 32. The light beams from the light sources 4L and 4R refracted by the eyepiece optical system 32 converge on the left and right exit pupils 1L and 1R, respectively (the light sources 4L and 4R and the exit pupils 1L and 1R are conjugate). At that time, since the left and right optical axes 2L and 2R intersect at a point P of 320 mm from the position of the exit pupils 1L and 1R to the eyepiece optical system 32 side, an image is formed on the Fresnel lens surface of the eyepiece optical system 32. The enlarged images for the left and right eyes with binocular parallax are fused in the vicinity of this point P, and it looks as if a stereoscopic image is displayed in the air.
[0048]
And based on this invention, as demonstrated with reference to FIG. 1, FIG. 2, the left and right eyeball positions of an observer are detected with the eyeball position detection apparatus 40, and the left and right illumination area | region of the illumination light source 4 based on the information By moving the light sources 4L and 4R, the positions of the left and right exit pupils 1L and 1R can be made to follow the positions of the observer's eyeballs, and even if the observer's observation position changes, the left and right exit pupils 1L and 1R A stereoscopic image can be observed in a wider range without overlapping, and a binocular image display device with a small number of parts, a small size, and low power consumption is obtained.
[0049]
In this embodiment, a lenticular sheet having diffusivity in the vertical direction is arranged near the plane of the eyepiece optical system 32 (three surfaces in the numerical data), and the pupil is enlarged only in the vertical direction for wider observation. A range can be secured.
[0050]
In this embodiment, all of the first surface 11 to the fourth surface 14 of the decentered prism 10 are free-form surfaces, and aspheric surfaces are used for the Fresnel transmission surfaces of the Fresnel lenses of the eyepiece optical system 32 and the illumination optical system 5. ing.
[0051]
In Example 2, the unilateral pupil diameter is 15 mm wide and 10 mm vertically, and the observation image is formed on the eyepiece optical system 32 having a horizontal size of 55 mm and a vertical size of 41.25 mm, 400 mm forward from the pupil position, and the left and right optical axes are inward. It exits from the eyepiece optical system 32 with an angle, and its inward angle intersects the eyepiece optical system 32 side from the pupil position at a position of 320 mm. As the left and right image display elements 3L and 3R, display elements of 8.94 mm × 6.71 mm are used.
[0052]
FIG. 15 is an optical path diagram from one light source (left illumination area at the reference position) 4L projected onto the YZ plane of the second embodiment to one exit pupil 1L, and FIG. 16 is an optical path projected onto the XZ plane. FIGS. 17A and 17B show optical path diagrams from the light sources 4L and 4R on both sides projected on the XZ plane to both exit pupils 1L and 1R.
[0053]
The numerical data described later is data of the optical system from the left exit pupil 1L through the image display element 3L to one light source 4L, and from the right exit pupil 1R through the image display element 3R to the other light source 4R. Is arranged in a plane-symmetrical position with the YZ plane as the plane of symmetry.
[0054]
The optical system of Example 2 is an optical system for a binocular image display device corresponding to the form of FIG. 4 as shown in FIGS. 15 to 17, and the relay optical system 31 has a YZ plane as a symmetry plane. This is an example in which a pair of plane-symmetric decentering prisms 10L and 10R are used, and left and right image display elements 3L and 3R are arranged facing each incident surface 11, and the illumination optical systems 5L and 5R are also separately provided. .
[0055]
In the optical system of this embodiment, as shown in FIGS. 15 to 17, the eyepiece optical system 32 facing the exit pupils 1L and 1R has a surface on the exit pupils 1L and 1R side having a Fresnel transmission surface and a surface on the opposite side being a plane. The reflecting surface (plane mirror) 33 for returning the optical path is disposed on the incident side, and the relay optical system 31 including the pair of decentering prisms 10L and 10R is disposed facing the reflecting surface 33. . The decentered prisms 10L and 10R of this embodiment include a first surface 11 facing the image display elements 3L and 3R, a fourth surface 14 facing the reflecting surface 33, and between the first surface 11 and the fourth surface 14, respectively. The decentering prisms 10L and 10R are plane-symmetric with respect to the symmetry plane (YZ plane) of the optical system as described above. It has a shape.
[0056]
The image display elements 3L and 3R are transmissive liquid crystal display elements. On the opposite side of the relay optical system 31 side, Fresnel lenses each having a double-sided Fresnel transmission surface are provided as the image display elements 3L as illumination optical systems 5L and 5R, respectively. The light sources 4L and 4R at the reference positions for the left and right optical paths are arranged at positions symmetrical with respect to the symmetry plane (YZ plane) in the vicinity of their front focal points.
[0057]
In this embodiment, left and right eye images with binocular parallax are displayed on the left and right image display elements 3L and 3R, and illuminated by the left and right light sources 4L and 4R via the left and right illumination optical systems 5L and 5R. The left and right decentering prisms 10L and 10R project the images of the left and right image display elements 3L and 3R in the vicinity of the common eyepiece optical system 32, and the left and right eyes located at the exit pupils 1L and 1R have parallax. Are displayed as a three-dimensional image.
[0058]
That is, the light beams emitted from the light sources 4L and 4R are made approximately parallel by the Fresnel lenses of the left and right illumination optical systems 5L and 5R, respectively, and illuminate the left and right image display elements 3L and 3R composed of transmissive liquid crystal display elements from the back. The display light is refracted by the first surfaces 11 of the left and right decentered prisms 10L and 10R, enters the prism, repeats internal reflection on the second surface 12 and the third surface 13, and is refracted by the fourth surface 14. The two light beams are emitted from the prism, and the two light fluxes are folded back by the reflecting surface 33, and the left and right eye enlarged images of the left and right image display elements 3L and 3R are formed on the Fresnel lens surface of the eyepiece optical system 32 as a double image. The light beams from the light sources 4L and 4R that are imaged and refracted by the eyepiece optical system 32 converge on the left and right exit pupils 1L and 1R, respectively (the light sources 4L and 4R and the exit pupils 1L and 1R are conjugate). At that time, since the left and right optical axes 2L and 2R intersect at a point P of 320 mm from the position of the exit pupils 1L and 1R to the eyepiece optical system 32 side, an image is formed on the Fresnel lens surface of the eyepiece optical system 32. The enlarged images for the left and right eyes with binocular parallax are fused in the vicinity of this point P, and it looks as if a stereoscopic image is displayed in the air.
[0059]
And based on this invention, as demonstrated with reference to FIG. 1, FIG. 2, the left and right eyeball positions of an observer are detected with the eyeball position detection apparatus 40, and the left and right illumination area | region of the illumination light source 4 based on the information By moving the light sources 4L and 4R, the positions of the left and right exit pupils 1L and 1R can be made to follow the positions of the observer's eyeballs, and even if the observer's observation position changes, the left and right exit pupils 1L and 1R Thus, a stereoscopic image can be observed in a wider range without overlapping, and a binocular image display device with a small size and low power consumption can be obtained.
[0060]
Also in this embodiment, a lenticular sheet having diffusivity in the vertical direction is arranged near the plane (three surfaces in the numerical data) of the eyepiece optical system 32, and the pupil is enlarged only in the vertical direction. An observation range can be secured.
[0061]
In this embodiment, free-form surfaces are used for the first surface 11 to the fourth surface 14 of the decentering prisms 10L and 10R, and the Fresnel transmission surfaces of the Fresnel lenses of the eyepiece optical system 32 and the illumination optical system 5 are aspherical surfaces. Is used.
[0062]
In Example 3, the unilateral pupil diameter is 10 mm, the observation image is formed on the eyepiece optical system 32 having a horizontal size of 55 mm and a vertical size of 41.25 mm, 400 mm forward from the pupil position, and the left and right optical axes have inward angles. It exits from the eyepiece optical system 32, and its inward angle intersects the eyepiece optical system 32 side from the pupil position at a position of 320 mm. As the image display element 3, a display element of 8.94 mm × 6.71 mm is used.
[0063]
FIG. 18 is an optical path diagram from one light source (left illumination region at the reference position) 4L projected onto the YZ plane of the third embodiment to one exit pupil 1L, and FIG. 19 is an optical path projected onto the XZ plane. FIG. 20, FIG. 20 is an optical path diagram from both light sources 4L, 4R projected onto the XZ plane to both exit pupils 1L, 1R, FIG. 21 is a diagram of light sources 4L, 4R, illumination optical system 5, and image display element of FIG. 3 shows an enlarged view of the vicinity of the decentered prism 10 of the relay optical system 31. FIG.
[0064]
The numerical data described later is data from the left exit pupil 1L through the image display element 3 to one light source 4L, and optical system data from the right exit pupil 1R through the image display element 3 to the other light source 4R. Is arranged in a plane-symmetrical position with the YZ plane as the plane of symmetry.
[0065]
In this embodiment, the eyepiece optical system 32 is different from the first embodiment in that the exit pupil 1L (1R) side surface is a free-form transmission surface 21, and the opposite surface is a Fresnel reflection surface 22. In this example, the reflecting surface 33 for turning back the optical path is omitted, and the fourth surface 14 (five surfaces in the numerical data) of the decentered prism 10 constituting the relay optical system 31 is a surface with the YZ plane as a symmetry plane. Only the one surface 14L, which is formed of a symmetrical discontinuous surface and is involved in the formation of the left exit pupil 1L, is shown. The surface 14L is provided on the X-axis negative side from the YZ plane, and the other surface 14R that is plane-symmetric with respect to the Y-Z plane is provided on the X-axis positive side (FIG. 21). By forming the fourth surface 14 as a discontinuous surface composed of two optical surfaces 14L and 14R that are symmetrical with respect to the symmetry plane, 75 mm can be obtained around the symmetry surface (YZ surface) of the optical system of the present embodiment. An optical system having left and right exit pupils 1L and 1R having a pupil diameter of 10 mm can be configured.
[0066]
As shown in FIGS. 18 to 21, in the optical system of the third embodiment, the eyepiece optical system 32 facing the exit pupil 1L (1R) is opposite to the transmission surface 21 having a free-form surface on the exit pupil 1L (1R) side. The side surface is composed of the Fresnel reflecting mirror 20 including the Fresnel reflecting surface 22, and the relay optical system 31 is disposed on the reflecting side. The relay optical system 31 includes a decentered prism 10 facing the image display element 3, and the decentered prism 10 of this embodiment includes a first surface 11 facing the image display element 3 and a fourth surface facing the eyepiece optical system 32. And the second surface 12 and the third surface 13 of the two reflecting surfaces disposed between the first surface 11 and the fourth surface 14, and the fourth surface 14 of the optical system is as described above. It consists of two surfaces 14L and 14R that constitute a discontinuous surface that is plane-symmetric with respect to the symmetry plane (YZ plane).
[0067]
Further, the image display element 3 is composed of a transmissive liquid crystal display element, and on the side opposite to the relay optical system 31 side, a Fresnel lens comprising a double-sided Fresnel transmissive surface as the illumination optical system 5 is disposed in the vicinity of the image display element 3. Near the front focal plane, light sources 4L and 4R for the left and right optical paths are arranged at positions symmetrical with respect to the symmetry plane (YZ plane) at the reference position.
[0068]
In this embodiment, left and right eye images with binocular parallax are alternately displayed on the image display element 3, and the light sources 4L and 4R for the left and right optical paths are selectively lit in synchronization with the switching, The right and left eye images with parallax are displayed on the left and right eyes located at the exit pupils 1L and 1R in a time-sharing manner and displayed as a stereoscopic image.
[0069]
That is, the light beams emitted from the light sources 4L and 4R are made substantially parallel by the Fresnel lens of the illumination optical system 5, respectively, illuminate the image display element 3 composed of a transmissive liquid crystal display element from the back, and the display light is decentered prism 10. The first surface 11 is refracted and incident on the prism, the internal reflection is repeated on the second surface 12 and the third surface 13, and the two surfaces 14L and 14R of the fourth surface 14 as light beams along different optical paths. The two light beams are refracted and emitted outside the prism, and the enlarged images for the left and right eyes of the image display element 3 are formed as double images on the transmission surface 21 of the Fresnel reflecting mirror 20 of the eyepiece optical system 32, The light beams from the light sources 4L and 4R reflected by the eyepiece optical system 32 converge on the left and right exit pupils 1L and 1R, respectively (the light sources 4L and 4R and the exit pupils 1L and 1R are conjugate). At that time, since the left and right optical axes 2L and 2R intersect at a point P of 320 mm from the position of the exit pupils 1L and 1R to the eyepiece optical system 32 side, an image is formed on the transmission surface 21 of the Fresnel reflector 20. The enlarged images for the left and right eyes with binocular parallax are fused in the vicinity of this point P, and it looks as if a stereoscopic image is displayed in the air.
[0070]
And based on this invention, as demonstrated with reference to FIG. 1, FIG. 2, the left and right eyeball positions of an observer are detected with the eyeball position detection apparatus 40, and the left and right illumination area | region of the illumination light source 4 based on the information By moving the light sources 4L and 4R, the positions of the left and right exit pupils 1L and 1R can be made to follow the positions of the observer's eyeballs, and even if the observer's observation position changes, the left and right exit pupils 1L and 1R A stereoscopic image can be observed in a wider range without overlapping, and a binocular image display device with a small number of parts, a small size, and low power consumption is obtained.
[0071]
In this embodiment, a free curved surface is used for all of the first surface 11 to the fourth surface 14 of the eccentric prism 10, a free curved surface is used for the transmitting surface 21 of the Fresnel reflecting mirror 20, and the Fresnel of the Fresnel reflecting mirror 20. An aspherical surface is used for the reflection surface 22 and the Fresnel transmission surface of the Fresnel lens of the illumination optical system 5.
[0072]
Numerical data of each example is shown below. In the table below, “FFS” is a free-form surface, “ASS” is an aspheric surface, “RE” is a reflective surface, “FR” is a Fresnel surface, and “LCD” is an image. The display surface, “EIM”, indicates the image plane.
[0073]

[0074]

[0075]

[0076]
The lateral aberration of the optical system on one side of Example 1 is shown in FIG. In this lateral aberration diagram, the numbers shown in parentheses represent (horizontal field angle, vertical field angle), and represent lateral aberration at that field angle.
[0077]
In the above three embodiments, transmissive liquid crystal display elements are used as the image display elements 3, 3L, and 3R. Instead, reflective liquid crystal display elements, DMDs (digital micromirror devices), and the like. By using this reflective image display element, it is possible to configure an image display device that can be stereoscopically viewed with a smaller and more compact configuration and lower power consumption. In that case, as illustrated in FIG. 5, illumination from the left and right illumination areas 4L and 4R of the illumination light source 4 through part or all of the decentered prisms 10, 10L, and 10R constituting the relay optical system 31 is performed. The display surface of the reflective image display element 3 is irradiated with light, and the display light modulated on the display surface is incident again on the eccentric prisms 10, 10L, 10R of the relay optical system 31, thereby causing the left and right exit pupils 1L, 1R. Projection is performed along the optical axes 2L and 2R.
[0078]
By the way, as the illumination light source 4 that can arbitrarily move the illumination regions 4L and 4R based on the left and right eyeball position information of the observer detected by the eyeball position detection device 40, a two-dimensional array of LEDs, a two-dimensional organic EL, and a backlight are used. A transmissive liquid crystal display element or the like irradiated with the above can be used, but a pair of openings arranged in front of a surface light source and the openings can be moved mechanically, or a pair of mechanically movable points It may consist of a light source.
[0079]
The movement range of the illumination areas 4L and 4R can be moved within a range in which light rays are not vignetted by the relay optical system 31 and the eyepiece optical system 32.
[0080]
Further, the decentered prism optical system used in the relay optical system of the binocular image display device of the present invention is not limited to the type used in the first to third embodiments, and other types of decentered prisms alone or their decenters. An optical system composed of a combination of prisms can be used.
[0081]
The binocular image display device of the present invention described above can be configured as follows, for example.
[0082]
[1] An image display element for displaying an image, an illumination light source, an illumination optical system for irradiating illumination light from the illumination light source toward the image display element, and display light modulated by the image display element In an image display device having a relay optical system that projects an image displayed on the image display element, and an eyepiece optical system that converges a light beam from the relay optical system on an exit pupil,
The image display element comprises a single image display element that alternately displays images for left and right eyes,
The illumination light source is a light source that is switched to separate illumination areas according to the left and right eye images displayed on the image display element, and that can move the illumination area,
The exit pupil consists of a pair of left and right exit pupils determined according to the illumination area of the illumination light source,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
The left and right eyeball position information of the observer detected by the eyeball position detection apparatus so that the pair of left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection apparatus. The binocular image display device is characterized in that the illumination area of the illumination light source is moved based on the above.
[0083]
[2] The binocular according to the above 1, wherein the relay optical system is configured to form an image for left and right eyes displayed on the image display element in the vicinity of the eyepiece optical system. Image display device.
[0084]
[3] The relay optical system according to 1 or 2, wherein the relay optical system includes an optical system that divides a light beam emitted from an object displayed on the image display element into two optical paths. Binocular image display device.
[0085]
[4] The relay optical system includes a decentered prism formed of a medium having a refractive index (n) larger than 1 (n> 1), and the decentered prism prisms a light beam emitted from the object point. A light incident surface, at least one reflecting surface for reflecting the light beam inside the prism, an exit surface for emitting the light beam outside the prism, and at least one rotationally asymmetric surface, 3. The above-mentioned item 3, wherein one optical action surface is constituted by a discontinuous surface composed of at least two adjacent surfaces, and the other optical action surface is commonly arranged in at least two divided optical paths. Binocular image display device.
[0086]
[5] The image display element is a reflective image display element, and illumination light from the illumination area of the illumination light source is applied to the reflective image display element via part or all of the eccentric prism. 5. The binocular image display device as described in 4 above.
[0087]
[6] The binocular image display device according to any one of 1 to 4, wherein the image display element is a transmissive image display element.
[0088]
[7] The binocular image display device according to any one of [1] to [5], wherein the illumination light source is a surface light source capable of setting an illumination area at an arbitrary position.
[0089]
[8] An image display element for displaying an image, an illumination light source, an illumination optical system for irradiating illumination light from the illumination light source toward the image display element, and display light modulated by the image display element In an image display device having a relay optical system that projects an image displayed on the image display element, and an eyepiece optical system that converges a light beam from the relay optical system on an exit pupil,
The image display element comprises a pair of image display elements that display images for left and right eyes,
The illumination light source includes a separate illumination area corresponding to the pair of image display elements, and includes a light source that can move the illumination area.
The exit pupil consists of a pair of left and right exit pupils determined according to the illumination area of the illumination light source,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
The left and right eyeball position information of the observer detected by the eyeball position detection apparatus so that the pair of left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection apparatus. The binocular image display device is characterized in that the illumination area of the illumination light source is moved based on the above.
[0090]
[9] The binocular according to 8, wherein the relay optical system is configured to form an image for left and right eyes displayed on the image display element in the vicinity of the eyepiece optical system. Image display device.
[0091]
[10] The relay optical system includes an optical system that guides light beams emitted from the object points to separate optical paths using the left and right eye images displayed on the image display element as object points, respectively. The binocular image display device according to 8 or 9.
[0092]
[11] The relay optical system includes a pair of decentered prisms formed of a medium having a refractive index (n) larger than 1 (n> 1), and each decentered prism is emitted from a corresponding image display element. A light incident surface that enters the prism, at least one reflecting surface that reflects the light within the prism, and an exit surface that emits the light out of the prism. 11. The binocular image display device as described in 10 above, comprising a rotationally asymmetric surface for providing power.
[0093]
[12] The image display element is a reflection-type image display element, and illumination light from the illumination area of the illumination light source is applied to the reflection-type image display element via part or all of the eccentric prism. 12. The binocular image display device as described in 11 above.
[0094]
[13] The binocular image display device as described in any one of 8 to 11, wherein the image display element is a transmissive image display element.
[0095]
[14] The binocular image display device according to any one of [8] to [13], wherein the illumination light source is a surface light source capable of setting an illumination area at an arbitrary position.
[0096]
【The invention's effect】
As is clear from the above description, according to the present invention, even if the observer's observation position is moved, the right-eye pupil and the left-eye pupil can be tracked without overlapping so that stereoscopic viewing in a wider range can be performed. Thus, a portable binocular image display apparatus with a small number of parts and a small number of parts can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a basic form of a binocular image display device of the present invention.
FIG. 2 is a diagram for explaining in detail the operation of the binocular image display device of the present invention.
FIG. 3 is a schematic perspective view showing a configuration of a binocular image display device in a case where a relay optical system is configured from a single decentered prism.
FIG. 4 is a schematic perspective view illustrating a configuration of a binocular image display device in a case where a relay optical system includes a pair of decentered prisms.
FIG. 5 is a schematic perspective view showing an example of a single decentered prism constituting the relay optical system and an example of the arrangement of illumination light sources and the method of introducing illumination light when the image display element is configured as a reflection type.
FIG. 6 is a diagram showing an exit pupil formed as an ellipse that is long on the left and right.
FIG. 7 is a diagram for explaining the diffusibility of a diffusive optical surface arranged in an eyepiece optical system.
FIG. 8 is a schematic perspective view showing a binocular image display device of the present invention configured in a handheld viewer type configuration.
FIG. 9 is an optical path diagram from one light source projected onto the YZ plane of the optical system according to the first embodiment of the present invention to one exit pupil.
10 is an optical path diagram projected onto the XZ plane of the optical system of Example 1. FIG.
11 is an optical path diagram from the light sources on both sides projected to the XZ plane of the optical system of Example 1 toward both exit pupils. FIG.
12 is an enlarged view in the vicinity of a decentered prism of the light source, illumination optical system, image display element, and relay optical system of FIG.
FIG. 13 is an imaging optical path diagram corresponding to FIG. 9;
14 is an imaging optical path diagram corresponding to FIG.
15 is an optical path diagram from one light source projected onto the YZ plane of the optical system of Example 2 toward one exit pupil. FIG.
16 is an optical path diagram projected onto the XZ plane of the optical system of Example 2. FIG.
FIG. 17 is an optical path diagram from the light sources on both sides projected onto the XZ plane of the optical system of Example 2 toward both exit pupils.
FIG. 18 is an optical path diagram from one light source projected onto the YZ plane of the optical system of Example 3 toward one exit pupil.
19 is an optical path diagram projected onto the XZ plane of the optical system of Example 3. FIG.
20 is an optical path diagram from the light sources on both sides projected to the XZ plane of the optical system of Example 3 toward both exit pupils. FIG.
21 is an enlarged view in the vicinity of a decentered prism of the light source, illumination optical system, image display element, and relay optical system of FIG.
22 is a diagram showing transverse aberration of the optical system on one side of Example 1. FIG.
[Explanation of symbols]
1L, 1R ... exit pupil
2L, 2R ... Optical axis
3, 3L, 3R ... Image display element
4 ... Illumination light source
4L, 4R ... Illumination area
5, 5L, 5R ... Illumination optical system
10, 10L, 10R ... Eccentric prism
11 ... first side
12 ... the second side
13 ... Third surface
14 ... Fourth side
14L, 14R: Optical surfaces constituting discontinuous surfaces
20 ... Fresnel reflector
21 ... Transmission surface on the exit pupil side of the eyepiece optical system
22 ... Fresnel reflecting surface on the opposite side of the eyepiece optical system
30 ... Display device body
31 ... Relay optical system
32 ... Eyepiece optical system
33 ... Reflecting surface (plane mirror)
34 ... Operation buttons
40. Eye position detection device
41. Imaging device
42. Video processing device
43. Control device

Claims (8)

An image display element for displaying an image, an illumination light source, an illumination optical system for irradiating illumination light from the illumination light source toward the image display element, and a relay optical system for projecting an image displayed on the image display element And an eyepiece optical system that converges the light flux from the relay optical system to an exit pupil position,
The image display element comprises a single element that alternately displays images for left and right eyes,
The illumination light source is configured to be able to switch the illumination area according to the left and right eye images, and to be able to move the illumination area,
The exit pupil position is a conjugate position with the illumination area of the illumination light source, and a pair of left and right exit pupils are formed at the exit pupil position,
The shape of the exit pupil of the relay optical system formed at the exit pupil position is an ellipse that is long to the left and right,
The eyepiece optical system has a diffusive optical surface;
The diffusive optical surface is a surface having a diffusing action in the up-down direction and hardly diffusing in the left-right direction,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
Illumination of the illumination light source based on the left and right eyeball position information of the observer so that the positions of the left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection device. A binocular image display device characterized by moving an area. An image display element for displaying an image, an illumination light source, an illumination optical system for irradiating illumination light from the illumination light source toward the image display element, and a relay optical system for projecting an image displayed on the image display element And an eyepiece optical system that converges the light flux from the relay optical system to an exit pupil position,
The image display element is composed of a pair of elements for displaying left and right eye images,
The illumination light source includes separate illumination areas corresponding to the pair of elements, and is configured to be movable in the illumination areas.
The exit pupil position is a conjugate position with the illumination area of the illumination light source, and a pair of left and right exit pupils are formed at the exit pupil position,
The shape of the exit pupil of the relay optical system formed at the exit pupil position is an ellipse that is long to the left and right,
The eyepiece optical system has a diffusive optical surface;
The diffusive optical surface is a surface having a diffusing action in the up-down direction and hardly diffusing in the left-right direction,
Furthermore, it has an eyeball position detection device that detects the left and right eyeball positions of the observer,
Illumination of the illumination light source based on the left and right eyeball position information of the observer so that the positions of the left and right exit pupils substantially coincide with the left and right eyeball positions of the observer detected by the eyeball position detection device. A binocular image display device characterized by moving an area.   The binocular image display device according to claim 1, wherein the illumination light source has a two-dimensional array shape.   4. The binocular image display device according to claim 3, wherein the illumination light source is any one of a two-dimensional array of LEDs, a two-dimensional organic EL, and a transmissive liquid crystal display element irradiated with a backlight.   The binocular image display device according to claim 1, wherein the illumination light source includes a surface light source, an opening disposed in front of the surface light source, and a moving mechanism that moves the opening.   The binocular image display device according to claim 1, wherein the illumination light source includes a point light source and a moving mechanism that moves the point light source. The ocular optical system Fresnel lens and the reflecting mirror, or binocular image display apparatus according to any one of 6 claim 1 characterized by comprising a Fresnel reflector. The relay optical system binocular image display apparatus according to any one of 7 from claim 1 characterized by comprising the decentered prism.

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